Scroll Fluidic Device

ABSTRACT

Provided is a scroll fluidic device that is capable of reducing suction pressure loss as well as suppressing discharge pulsations and reducing noise. The scroll fluidic device is characterized in that a fixed scroll member is integrally formed with a center housing on the inside of the center housing disposed between a front housing and a rear housing; the end surface of the outer shell of the center housing is positioned lower than the height of a scroll lap of the fixed scroll member, with an end plate of the fixed scroll member served as a reference of position in the height direction; and a corridor-like space extending in the device circumferential direction, which is surrounded by an outer shell forming portion of the center housing, the inner surface of an outer shell of the front housing, the scroll lap of the fixed scroll member, and the end plate of a movable scroll member, is formed.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a scroll fluidic device usable as a compressor or an expander, and specifically, to a structure of a device housing portion thereof.

BACKGROUND ART OF THE INVENTION

A scroll fluidic device is well known wherein a scroll lap is formed on an end plate of a fixed scroll member integrally with the end plate, a scroll lap is formed on an end plate of a movable scroll member integrally with the end plate, both scroll members are disposed so that angles of both scroll laps are shifted from each other and side walls of both scroll laps are partially brought into contact with each other, a volume of a fluid pocket, which is a closed space formed between both scroll laps, is changed by moving the fluid pocket from an outer end section of the scroll laps toward a center section of the scroll laps in case of a compressor or from the center section of the scroll laps toward the outer end section of the scroll laps in case of an expander by revolving the movable scroll member on a circular orbit at a condition preventing rotation of the movable scroll member, and the fluid taken in the fluid pocket is compressed or expanded accompanying with the volume change of the fluid pocket.

In such a scroll fluidic device, in particular, in a scroll compressor, it is strongly desired to achieve reduction of suction pressure loss (for example, Patent document 1) or reduction of discharge pulsation and noise (for example, Patent document 2), and further, small-sized and lightened structure in case of use for an air conditioning system for vehicles, etc. (Patent documents 1 and 2).

In Patent document 1, a structure is disclosed wherein a fixed scroll member is integrally formed with a center housing in the center housing, an outer end portion of the scroll lap of the fixed scroll member is formed integrally with the housing so as to be connected to the inner circumferential surface of the housing, thereby forming a large width portion, and to this large width portion, provided is a communication path for communication between a suction chamber and the fluid pocket. In this structure, the end surface of the outer shell of the center housing connected to a front housing is located at a position higher than the height of the scroll lap of the fixed scroll member in an axial direction, and it is structured so that the outer shell of the center housing completely envelops the fixed scroll member.

In Patent document 2, a structure is disclosed wherein a sub-housing is provided to an outer circumferential side of the center housing, therein a second discharge chamber communicating with a first discharge chamber through a communication path is provided, and by providing a discharge port relatively to the second discharge port, discharge pulsation is suppressed and noise is reduced.

PRIOR ART DOCUMENTS Patent Documents

-   Patent document 1: Japanese Patent No. 3,144,611 -   Patent document 2: Japanese Patent No. 3,206,221

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

There is no proposal of pulsation reduction means for a case of compressor in Patent document 1, and for discharge pulsation, separately Patent document 2 discloses a structure devised with a discharge chamber as described above. However, the location of the second discharge chamber provided on the outer circumferential side of the center housing proposed in Patent document 2 and the location of the communication path proposed in Patent document 1 are present at positions interfering with each other or at positions close to each other. Therefore, if the volume of the second discharge chamber in Patent Document 2 is tried to be made larger in order to enhance suppression of discharge pulsation and reduction of noise, the cross-sectional area of the communication path provided to the fixed scroll member is to be decreased, and undesired suction pressure loss may occur. Therefore, from these both proposals, it is difficult to achieve reduction of suction pressure loss as well as suppression of discharge pulsation and reduction of noise, and it is further difficult to achieve those while trying to make the compressor smaller in size and lighter in weight.

Accordingly, paying attention to the above-described problems, an object of the present invention is to provide a scroll fluidic device which can achieve suppression of discharge pulsation as well as reduction of noise.

Further, an object of the present invention is to provide a scroll fluidic device which, while achieving both of the above-described matters, desirably, can achieve to make the device smaller in size and lighter in weight, and in addition, can realize those by a simple improved structure as well as can stably obtain a good product quality.

Means for Solving the Problems

To achieve the above objects, a scroll fluid device according to the present invention wherein a scroll lap is formed on an end plate of a fixed scroll member integrally with the end plate, a scroll lap is formed on an end plate of a movable scroll member integrally with the end plate, both scroll members are disposed so that angles of both scroll laps are shifted from each other and side walls of both scroll laps are partially brought into contact with each other, and a volume of a fluid pocket, which is a closed space formed between both scroll laps, is changed by moving the fluid pocket from an outer end section of the scroll laps toward a center section of the scroll laps or from the center section of the scroll laps toward the outer end section of the scroll laps by revolving the movable scroll member on a circular orbit at a condition preventing rotation of the movable scroll member, is characterized in that the fixed scroll member is integrally formed with a center housing, which is disposed between a front housing and a rear housing of the scroll fluidic device, in the center housing; an end surface of an outer shell of the center housing is positioned lower than a height of the scroll lap of the fixed scroll member, with the end plate of the fixed scroll member served as a reference of position in a height direction; and a corridor-like space extending in a device circumferential direction, which is surrounded by an outer shell forming portion of the center housing, an inner surface of an outer shell of the front housing, the scroll lap of the fixed scroll member, and the end plate of the movable scroll member, is formed. This scroll fluidic device according to the present invention is formed as a scroll compressor in case where the fluid pocket is moved from the outer end section toward the center section, and formed as a scroll expander is moved from the center section toward the outer end section of the scroll laps.

In such a scroll fluidic device according to the present invention, by setting the condition where the end surface of the outer shell of the center housing is positioned lower than the height of the scroll lap of the fixed scroll member, as shown in the respective embodiments described later, it becomes possible to efficiently form a corridor-like space extending the device circumferential direction at a position of the end plate side of the movable scroll member or the inner surface side of the front housing in the outer circumferential side of the scroll lap of the fixed scroll member. Namely, it becomes possible to efficiently form a corridor-like space extending the device circumferential direction at a place which has not been paid attention to at all. Since this corridor-like space is located at a halfway position (a route position) of a flow path of suction fluid from a suction chamber to a fluid pocket in case where the scroll fluidic device is formed as a scroll compressor, it can contribute to reduce the suction pressure loss by being formed in an adequate shape, and since it is located at a halfway position (a route position) of a flow path of expansion fluid from a fluid pocket to a discharge chamber in case where the scroll fluidic device is formed as a scroll expander, it can contribute to reduce the discharge pressure loss and to reduce the discharge pulsations by being formed in an adequate shape. Further, since this corridor-like space is formed by effectively utilizing a place at the front housing side in the outer circumferential side of the scroll lap of the fixed scroll member, for this corridor-like space, with respect to a place at the outer circumferential side of the scroll lap of the fixed scroll member and at the rear housing side (namely, a place which is located at the rear housing side relatively to the corridor-like space and at a position which does not interfere with the corridor-like space forming place and which is different in the device axial direction), it becomes possible to employ various designs. For example, as described later, it becomes possible to efficiently form a second discharge chamber in this place without particularly making a compressor large-sized, and by forming such a second discharge chamber, reduction of discharge pulsation and reduction of noise become possible. Further, it also becomes possible to form a wall of the center housing at this place appropriately small (thin), namely, to provide an adequate thickness relief portion, thereby efficiently making the device small in size and light in weight. Furthermore, it becomes also possible to form the above-described second discharge chamber by utilizing such a thickness relief portion.

Further, in the scroll fluidic device according to the present invention, a structure may be employed wherein, at a phase angle at which a distance between an inner surface of an outer circumferential end of the scroll lap of the movable scroll member and an outer surface of the scroll lap of the fixed scroll member facing to the inner surface of the outer circumferential end of the scroll lap of the movable scroll member becomes maximum, a cross-sectional area A1 of the corridor-like space satisfies the following relationship with a sectional area A2 of a port provided on the front housing.

A2/2<A1<A2

Although a pair of fluid pockets whose shift angles are shifted from each other by about 180 degrees are formed between the scroll laps of the fixed scroll member and the movable scroll member, if supposed is a suction route of a compressor wherein suction fluid is taken into the fluid pockets from a suction port provided on the front housing through the corridor-like space, if it is considered that the suction fluid from the suction port is taken into the pair of fluid pockets respectively in one rotation, in order to avoid increase of suction pressure loss caused by compression of the fluid when passing through the corridor-like space, it is preferred that the cross-sectional area A1 of the corridor-like space is ½ or more of the sectional area A2 of the suction port. Further, because an amount of fluid more than the amount of fluid sucked from the suction port is never taken into the respective fluid pockets, it is enough that the cross-sectional area A1 of the corridor-like space has an area corresponding to the sectional area A2 of the suction port at largest. Therefore, the above-described relationship is preferably satisfied in order to maintain the small-sized and light-weight property of the whole of the device without unnecessarily making the corridor-like space large while obtaining the aforementioned advantages due to forming of the corridor-like space. Also in case of a scroll expander, the flow direction of fluid is only reversed, and the above-described preferable relationship is same.

Further, in the scroll fluidic device according to the present invention, a structure can be employed wherein the corridor-like space is always opened to a suction chamber of suction fluid or a discharge chamber of expansion fluid which is positioned at a side opposite to a side of the fixed scroll member with reference to the end plate of the movable scroll member. In such a structure, because the corridor-like space is always opened to a suction chamber of suction fluid or a discharge chamber of expansion fluid, it becomes possible to move the fluid without generating a large pressure loss or pulsation therebetween, and a stable operation can be realized.

Further, a structure can also be employed wherein a port directly fronting the corridor-like space is provided to the front housing. In such a structure, for example, the fluid sucked from the suction port always flows directly into the corridor-like space as it is, and therethrough it is taken into the fluid pocket. Therefore, a desirable suction route is always formed stably, and a stable operation becomes possible.

Further, in the scroll fluidic device according to the present invention, a structure can be employed wherein, on an outer surface side of the outer shell of the center housing, a recessed outer surface of the outer shell having a predetermined thickness is formed relatively to a wall forming a wall surface, which contributes to change of volume of the fluid pocket, and a wall forming a wall surface, which faces the corridor-like space, of the scroll lap of the fixed scroll member. In such a structure, since the recessed outer surface is formed on the outer surface of the outer shell of the center housing so as to be adjacent to the corridor-like space, by an amount corresponding to the recessed outer surface, the device can be made small in size and light in weight.

Although the above-described recessed outer surface has a form opened toward outside of the device in a radial direction, in the scroll fluidic device according to the present invention, it is also possible to provide an internal-type space. For example, a structure can be employed wherein, on an inner surface side of the outer shell of the above-described center housing, a cup-like thickness relief portion extending in the same direction as the height direction of the scroll lap of the fixed scroll member is provided between a wall forming a wall surface, which contributes to change of volume of the fluid pocket, of the scroll lap of the fixed scroll member, and a wall forming an outer surface of the outer shell. By forming such a thickness relief portion on the inner surface side of the outer shell of the above-described center housing, lightening becomes possible by an amount corresponding to the thickness relief portion. Further, it is also possible to give various functions to this thickness relief portion by employing various structures as follows.

As the above-described thickness relief portion, a structure may be employed wherein the portion opens toward a side of the rear housing. At that time, it can be formed as a device interior space which is not directly opened to outside of the device, thereby giving various functions.

For example, in case of a scroll compressor, a structure can be employed wherein the above-described thickness relief portion forms a second discharge chamber communicating with a first discharge chamber (a discharge chamber for the fluid compressed by the scroll laps) formed in the rear housing via a throttled portion. By forming such a second discharge chamber following the first discharge chamber on the route of discharge fluid, a buffer function relative to pulsation of the fluid in the discharge route and a silencer function can be given to the second discharge chamber, and it becomes possible to obtain an excellent effect for reducing discharge pulsation and reducing noise.

For example, in case of a scroll compressor, a structure can be employed wherein the thickness relief portion forms a second discharge chamber communicating with a first discharge chamber formed in the rear housing (a discharge chamber for the fluid compressed by scroll laps) via a throttled portion. By forming such a second discharge chamber following the first discharge chamber on the route of discharge fluid, a buffer function relative to pulsation of the fluid in the discharge route and a silencer function can be given to the second discharge chamber, and it becomes possible to obtain an excellent effect for reducing discharge pulsation and reducing noise.

Further, although the structure of the above-described throttled portion is not particularly restricted, for example, a structure can be employed wherein the above-described throttled portion is formed by an inner outline of a gasket sealing between the center housing and the rear housing and an outline of an opening portion of the second discharge chamber. In such a structure, it is not necessary to add a special member for forming the throttled portion.

Further, in case where the thickness relief portion opening toward the rear housing side is provided as described above, a structure may be employed wherein the thickness relief portion forms an oil storage chamber communicating with a discharge chamber formed in the rear housing for storing oil present in the discharge chamber. In such a structure, an oil storing space can be formed substantially in the discharge chamber, and by employing a structure in which the stored oil can be adequately returned to a drive section of suction side, a desired compressor lubrication state can be realized.

In case of such a structure, it is preferred that a filter is provided between the oil storage chamber and the discharge chamber. By providing a filter, it can be prevented that foreign materials and the like flow in at the time of oil returning. Further, it is preferred that the oil storage chamber and the corridor-like space are communicated with each other through an orifice. By interposing the orifice, it becomes possible to ensure an adequate amount of oil returning.

Further, in case where the thickness relief portion opening toward the rear housing side is provided as described above, a structure can also be employed wherein a discharge chamber and a suction chamber are formed via a partition wall in the rear housing, and the suction chamber communicates with the corridor-like space through the thickness relief portion. Namely, a space similar to the above-described second discharge chamber is formed by the thickness relief portion, and this space portion is used as a part of the suction route. For example, it is an effective structure in case where it is necessary to provide a suction port and a discharge port to the rear housing from limitation of disposition of equipment, and even in such a case, the corridor-like space can be formed as an effective space for reducing the suction pressure loss before the fluid is taken into the fluid pocket.

Furthermore, in case where the aforementioned cup-like thickness relief portion is provided, a structure can also be employed wherein the thickness relief portion opens toward a side opposite to the rear housing side, namely, toward a side of the front housing. In this case, since the thickness relief portion formed adjacent to the corridor-like space is to open toward the corridor-like space, it becomes possible to realize a structure wherein this thickness relief portion communicates with the corridor-like space, and a fluid route comprising a space formed by the thickness relief portion and the following corridor-like space is formed. Further, in this case, with respect to the thickness relief portion extending in the device circumferential direction with an appropriate length, a structure can also be employed wherein a cross-sectional area of the thickness relief portion changes in the device circumferential direction. By adequately changing the cross-sectional area in the device circumferential direction, for example, in case where a fluid suction route comprising a space formed by the thickness relief portion and the following corridor-like space is formed, it becomes possible to carry out the taking of the suction fluid into the corridor-like space and taking of the fluid from the corridor-like space into the fluid pockets more smoothly. Further, by smoothly changing the cross-sectional area, a further reduction of suction pressure loss may be possible. Furthermore, since the cup-like thickness relief portion opening toward the front housing side is provided to the center housing, for example, in a case a scroll compressor, it is possible to provide a suction port into this thickness relief portion to the center housing (on the outer shell of the center housing).

As aforementioned, the structure of the scroll fluidic device according to the present invention can be applied to any of a scroll compressor and a scroll expander, and in particular, it is suitable as a compressor for an air conditioning system for vehicles to which reduction of suction pressure loss, reduction of discharge pulsations, reduction of noise, and further, making small in size and light in weight are strongly required.

Effect According to the Invention

Thus, in the scroll fluidic device according to the present invention, in case where it is used as a compressor, reduction of suction pressure loss, and suppression of discharge pulsations and reduction of noise, can be both realized. Further, even in case where it is used not only as a compressor but also as an expander, the pressure loss at the discharge side, in particular, at the outer circumferential end of the movable side scroll lap and its vicinity, can be suppressed to be small.

Further, since the above-described improvement of performance can be efficiently achieved by forming the corridor-like space by effectively utilizing the section including the outer shell of the center housing which has not been paid attention to in the conventional technology, the aimed object can be achieved while realizing to make the center housing small in size and light in weight, ultimately, to make the whole of the device in size and light in weight, as compared with the aforementioned conventional structure.

Further, by forming the recessed outer surface or the thickness relief portion on the center housing, it becomes possible to make the center housing further light in weight. Further, since a thick portion can be abolished and the respective portions can be formed relatively thin and uniform in thickness, the center housing, ultimately, the whole of the device, can be made to be further light in weight. Further, in case where the center housing is formed by casting, etc., defects such as blow holes can be hardly generated because of the structure having a uniform thickness, and therefore, the quality for production is stabilized.

Furthermore, the above-described thickness relief portion can be utilized as a portion exhibiting various functions, it can contribute to suppression of discharge pulsations and reduction of noise, forming of an oil storage space, stable lubrication due to stable oil returning to drive sections, etc.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1 shows a vertical sectional view of a scroll fluidic device according to a first embodiment of the present invention (FIG. 1(A)), and a cross-sectional view thereof as viewed along arrows Y-Y of (A) (FIG. 1(B)).

FIG. 2 shows a vertical sectional view of a scroll fluidic device according to a second embodiment of the present invention (FIG. 2(A)), and a cross-sectional view thereof as viewed along arrows Y-Y of (A) (FIG. 2(B)).

FIG. 3 shows a vertical sectional view of a scroll fluidic device according to a third embodiment of the present invention (FIG. 3(A)), and cross-sectional view thereof as viewed along arrows Y-Y of (A) (FIG. 3(B)).

FIG. 4 shows a vertical sectional view of a scroll fluidic device according to a fourth embodiment of the present invention (FIG. 4(A)), and a cross-sectional view thereof as viewed along arrows Y-Y of (A) (FIG. 4(B)).

FIG. 5 shows a vertical sectional view of a scroll fluidic device according to a fifth embodiment of the present invention (FIG. 5(A)), and a cross-sectional view thereof as viewed along arrows Y-Y of (A) (FIG. 5(B)).

FIG. 6 is a vertical sectional view of a scroll fluidic device according to a sixth embodiment of the present invention.

FIG. 7 is a vertical sectional view of a scroll fluidic device according to a seventh embodiment of the present invention.

FIG. 8 is a vertical sectional view of a scroll fluidic device according to an eighth embodiment of the present invention.

FIG. 9 is a vertical sectional view of a scroll fluidic device according to a ninth embodiment of the present invention.

FIG. 10 shows a vertical sectional view of a scroll fluidic device according to a tenth embodiment of the present invention (FIG. 10(A)), and a cross-sectional view thereof as viewed along arrows Y-Y of (A) (FIG. 10(B)).

FIG. 11 is a vertical sectional view of a scroll fluidic device according to an eleventh embodiment of the present invention.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be explained referring to figures. Where, although the following embodiments will be explained as to a case where the present invention is applied to a scroll compressor, as aforementioned, the present invention can be basically applied also to a scroll expander.

FIG. 1 shows a scroll compressor as a scroll fluidic device according to a first embodiment of the present invention. In a scroll compressor 1 depicted in FIG. 1, a scroll lap 2 b is formed on an end plate 2 a of a fixed scroll member 2 integrally with the end plate 2 a, and a scroll lap 3 b is formed on an end plate 3 a of a movable scroll member 3 integrally with the end plate 3 a. Both scroll members 2, 3 are disposed so that the angles of both scroll laps 2 b, 3 b are shifted from each other and side walls of both scroll laps 2 b, 3 b are partially brought into contact with each other. The movable scroll member 3 is revolved on a circular orbit at a condition preventing rotation of the movable scroll member 3, and the volume of a fluid pocket 5 (fluid pockets formed as a pair form), which is a closed space formed between both scroll laps 2 b, 3 b, is changed in a direction contracting the volume of the fluid pocket 5 by moving the fluid pocket 5 from an outer end section of the scroll laps toward a center section of the scroll laps (in a case of an expander, it is reversely moved from a center section toward an outer end section), and the fluid (for example, refrigerant gas) taken from the outer end side of the scroll laps into the fluid pocket 5 is compressed.

The housing of compressor 1 comprises a front housing 6, a rear housing 7, and a center housing 8 disposed therebetween. In this embodiment, the above-described suction fluid is introduced from a suction port 9 provided to front housing 6 into a suction chamber 10, and therefrom, a part thereof is taken into the above-described fluid pocket 5 through a corridor-like space described later, and it is served to compression. The compressed fluid is discharged into a discharge chamber 12 formed in rear housing 7, through a discharge hole 11 formed in the central part of end plate 2 a of fixed scroll member 2, and therefrom, it is discharged to outside through a discharge port 13.

Symbol 14 shows a drive shaft, and a rotation drive force transmitted to a pulley 15 is transmitted to one end of the drive shaft 14 via an electromagnetic clutch 15, thereby rotating and driving the drive shaft 14. A crank mechanism 17 is formed on the other end of drive shaft 14, and movable scroll member 3 is driven so as to realize an orbital movement.

Fixed scroll member 2 is formed integrally with center housing 8 in the center housing 8 disposed between front housing 6 and rear housing 7. Then, the height of the position of an end surface 8 b of an outer shell 8 a of center housing 8 is set lower than the height of scroll lap 2 b of fixed scroll member 2, with the end plate 2 a of fixed scroll member 2 served as a reference of position in the height direction. Formed is a corridor-like space 18 extending in the device circumferential direction, which is surrounded by a forming portion of outer shell 8 a of this center housing 8, the inner surface of an outer shell 6 a of front housing 6, scroll lap 2 b of fixed scroll member 2, and end plate 3 a of movable scroll member 3. In this embodiment, this corridor-like space 18 communicates with suction chamber 10 which is positioned at a side opposite to a side of fixed scroll member 2 with reference to end plate 3 a of movable scroll member 3.

Further, in this embodiment, on the inner surface side of outer shell 8 a of center housing 8, a cup-like thickness relief portion 19 extending in the same direction as the height direction of scroll lap 2 b of fixed scroll member 2 is provided between a wall forming a wall surface, which contributes to change of the volume of fluid pocket 5, of scroll lap 2 b of fixed scroll member 2, and a wall forming the outer surface of outer shell 8 a. In this embodiment, this thickness relief portion 19 opens toward the side of rear housing 7, and communicates with discharge chamber 12 formed in rear housing 7.

In the scroll compressor 1 thus constructed, by setting the height of the position of end surface 8 b of outer shell 8 a of center housing 8 lower than the height of scroll lap 2 b of fixed scroll member 2, at the outer circumferential side of scroll lap 2 b of fixed scroll member 2, corridor-like space 18 extending in the device circumferential direction can be efficiently formed in a position at the inner surface side of front housing 6 by effectively utilizing a place which has not been paid attention to at all so far. It becomes possible to take the suction fluid into fluid pocket 5 from suction chamber 10 through this corridor-like space 18, and because the corridor-like space 18 is positioned on the way of the suction route, it becomes possible to reduce the suction pressure loss.

Further, since the above-described corridor-like space 18 is formed by utilizing a part of the portion occupied by center housing 8 as viewed in the device axial direction, by utilizing the remaining portion, it becomes possible to form thickness relief portion 19 as shown in the figure, adjacent to the corridor-like space 18. This thickness relief portion 19 is possible to be formed without particularly making the outline of the device larger, as compared with the aforementioned conventional structure wherein the second discharge chamber is formed by providing the sub housing. Therefore, as compared with such a conventional structure, it becomes possible to surely make the device small in size and light in weight. Because the volume of discharge chamber 12 can be increased by forming thickness relief portion 19 as depicted in the figure, reduction of discharge pulsations can be realized, thereby realizing reduction of noise. Furthermore, since a particular thick portion does not exist in center housing 8 and it becomes possible to make the thicknesses of the respective portions uniform, in case where center housing 8 is formed by casting, etc., defects such as blow holes can be prevented to be generated, and therefore, the quality for production can be stabilized.

FIG. 2 shows a scroll compressor as a scroll fluidic device according to a second embodiment of the present invention. In scroll compressor 21 depicted in FIG. 2, as compared with scroll compressor 1 depicted in FIG. 1, a cup-like thickness relief portion 23 formed in a center housing 22 opens toward the side of a front housing 24. A corridor-like space 25 is formed so as to communicate with the opening side of this cup-like thickness relief portion 23. Then, in this embodiment, a structure is employed wherein the cross-sectional area of thickness relief portion 23 extending in the device circumferential direction with an appropriate length changes in the device circumferential direction, and for example, in FIG. 2 (B), the portion greater in width of thickness relief portion 23 is formed deeper than the portion smaller in width. Since thickness relief portion 23 and corridor-like space 25 are communicated with each other so that their opening portions face to each other, the structure is formed so that the cross-sectional area of corridor-like space 25 is substantially enlarged, and so that the cross-sectional area of corridor-like space 25 changes in the device circumferential direction. Because the other structures are similar to those in the aforementioned first embodiment, explanation is omitted by providing the same symbols as those in FIG. 1 to FIG. 2.

In the scroll compressor 21 thus constructed, as compared with the aforementioned first embodiment, it becomes possible to more smoothly perform the suction of the suction fluid through corridor-like space 25 whose cross-sectional area is adequately changed, thereby further reducing the suction pressure loss.

FIG. 3 shows a scroll compressor as a scroll fluidic device according to a third embodiment of the present invention, and shows another lightening structure different from the above-described one due to the thickness relief portion in the center housing in the present invention, and a relationship between the cross-sectional areas of the corridor-like space and the suction port. In scroll compressor 31 depicted in FIG. 3, as compared with scroll compressor 1 depicted in FIG. 1, a structure is employed wherein, on the outer surface side of an outer shell 32 a of a center housing 32, a recessed outer surface 34 of the outer shell 32 a having a predetermined thickness is formed relatively to a wall 33 a forming a wall surface, which contributes to the change of volume of fluid pocket 5, and a wall 33 b forming a wall surface, which faces corridor-like space 18, of scroll lap 2 b of fixed scroll member 2. In such a structure, since recessed outer surface 34 is formed on the outer surface of outer shell 32 a of center housing 32 so as to be adjacent to corridor-like space 18, it becomes possible to make the device small in size and light in weight by an amount corresponding to this recessed outer surface 34.

Further, a desirable relationship between the cross-sectional areas of corridor-like space 18 and suction port 9 in the present invention will be explained utilizing FIG. 3. Namely, it is preferred that, when movable scroll member 3 is positioned at a phase angle at which a distance between an inner surface of the outer circumferential end of scroll lap 3 b of movable scroll member 3 and an outer surface of scroll lap 2 b of fixed scroll member 2 facing to the inner surface of the outer circumferential end of scroll lap 3 b of movable scroll member 3 becomes maximum, the relationship between a cross-sectional area A1 of the corridor-like space and a sectional area A2 of suction port 9 provided on front housing 6 satisfies the following relationship.

A2/2<A1<A2

In such a structure, as aforementioned, by corridor-like space 18 having an adequate size, a smooth operation can be ensured, and reduction of suction pressure loss can be realized. Because it is not necessary to make corridor-like space 18 unnecessarily, it can be accelerated to make the whole of the device small in size and light in weight. Because the other structures are similar to those in the aforementioned first embodiment, explanation is omitted by providing the same symbols as those in FIG. 1 to FIG. 3.

FIG. 4 shows a scroll compressor as a scroll fluidic device according to a fourth embodiment of the present invention. In scroll compressor 41 depicted in FIG. 4, as compared with scroll compressor 1 depicted in FIG. 1, a suction port 44 directly fronting a corridor-like space 43 is provided to a front housing 42. Symbol 42 a in FIG. 4(B) shows the inner circumference of front housing 42. In such a structure, the fluid sucked from suction port 44 can always flow directly into corridor-like space 43 as it is, and therefrom, it is taken into fluid pocket 5, and therefore, a desired suction route can be always formed stably, and a stable suction operation becomes possible. Because the other structures are similar to those in the aforementioned first embodiment, explanation is omitted by providing the same symbols as those in FIG. 1 to FIG. 4.

FIG. 5 shows a scroll compressor as a scroll fluidic device according to a fifth embodiment of the present invention. In scroll compressor 51 depicted in FIG. 5, as compared with scroll compressor 41 depicted in FIG. 4, in a case of providing thickness relief portion 19 opening toward the side of rear housing 7 and communicating with discharge chamber 12 formed in rear housing 7, the thickness relief portion 19 is positioned at a lower side in the posture installed with compressor 1, and the thickness relief portion 19 is formed so as to form an oil storage chamber 52 for storing oil in discharge chamber 12. Then, a filter 53 is provided between oil storage chamber 52 and discharge chamber 12, and by the filter 53, foreign matters and the like can be prevented from flowing in at the time of oil returning. Further, oil storage chamber 52 and corridor-like space 18 are communicated with each other through an orifice 54 (a small hole), and an adequate amount of oil is returned to the suction side, in particular, to a driving section in the suction side. In such a structure, an oil storage space can be efficiently formed substantially in discharge chamber 12 without making the compressor large-sized especially, the stored oil can be adequately returned to the drive section of the suction side, and a desirable lubrication state for the compressor can be realized. Because the other structures are similar to those in the aforementioned first embodiment, explanation is omitted by providing the same symbols as those in FIG. 1 to FIG. 5.

FIGS. 6-8 show scroll compressors as scroll fluidic devices according to sixth to eighth embodiments of the present invention. In scroll compressors 61, 71, 81 depicted in FIGS. 6-8, cup-like thickness relief portions 62, 72, 82 opening toward the side of rear housing 7 are formed, and the thickness relief portions 62, 72, 82 form second discharge chambers communicating with first discharge chambers 63, 73, 83 formed in rear housing 7 (discharge chambers for the fluid compressed by the scroll lap) via throttled portions 64, 74, 84. By forming such second discharge chambers 62, 72, 82 in the route of discharge fluid following first discharge chambers 63, 73, 83, the second discharge chambers 62, 72, 82 can be given with a buffer function against fluid pulsations in the discharge route, and a silencer function, and it becomes possible to obtain excellent effects for reducing discharge pulsations and reducing noise.

In scroll compressor 61 depicted in FIG. 6, a discharge port 65 discharging the compressed fluid from second discharge chamber 62 to outside of the device is provided to a center housing 66. In scroll compressor 71 depicted in FIG. 7, a discharge port 75 from second discharge chamber 72 is provided to a center housing 76, and the above-describe throttled portion 74 is formed by the inner outline of a gasket 77 sealing between center housing 76 and rear housing 7 and the outline of the opening portion of second discharge chamber 72, and by this, it becomes unnecessary to add a particular member for forming throttled portion 74. In scroll compressor 81 depicted in FIG. 8, a discharge port 85 is provided to the rear housing side not to the side of a center housing 86, and the fluid from second discharge chamber 82 is discharged to outside from the discharge port 85 through a communication hole 87. It can be appropriately selected at which position the discharge port is disposed, depending upon disposition environment of compressor or circumstances relative to other equipment and the like. Because the other structures are similar to those in the aforementioned first embodiment, explanation is omitted by providing the same symbols as those in FIG. 1 to FIGS. 6-8.

FIG. 9 shows a scroll compressor as a scroll fluidic device according to a ninth embodiment of the present invention. In scroll compressor 91 depicted in FIG. 9, thickness relief portion 19 opening toward the side of rear housing 7 in scroll compressor 41 depicted in FIG. 4 is not communicated with discharge chamber 12 formed in rear housing 7 as shown in FIG. 4, but is formed as a part of the suction route. Namely, a structure is employed wherein discharge chamber 12 and a suction chamber 93 are formed via a partition wall 92 in rear housing 7, and the suction chamber 93 communicates with corridor-like space 18 via a communication path 94 through the above-described thickness relief portion 19. In rear housing 7, a suction port 95 communicating with suction chamber 93 is provided, and at another position, a discharge port 96 communicating with discharge chamber 12 is provided. Such a structure is effective particularly in a case where it is necessary to both of suction port 95 and discharge port 96 to rear housing 7 from the relationship with equipment disposed around it, etc. Even in such a case, corridor-like space 18 can be utilized as a space effective for reducing the suction pressure loss before the fluid is taken into fluid pocket 5. Because the other structures are similar to those in the aforementioned first embodiment, explanation is omitted by providing the same symbols as those in FIG. 1 to FIG. 9.

FIG. 10 shows a scroll compressor as a scroll fluidic device according to a tenth embodiment of the present invention. In scroll compressor 101 depicted in FIG. 10, cup-like thickness relief portion 23 opening toward the side of front housing 24 in scroll compressor 21 depicted in FIG. 2 is formed as a part of a suction path 102, and a suction port 104 directly communicating with the inside of the suction space formed by thickness relief portion 23 is provided to a center housing 103. The suction path 102 can be efficiently formed by this thickness relief portion 23 and corridor-like space 25. Thus, the structure of suction path 102 can also be designed with a great freedom. Because the other structures are similar to those in the aforementioned first embodiment, explanation is omitted by providing the same symbols as those in FIG. 1 to FIG. 10.

FIG. 11 shows a scroll compressor as a scroll fluidic device according to a eleventh embodiment of the present invention. Although scroll compressor 111 depicted in FIG. 11 has a structure similar to that of scroll compressor 31 depicted in FIG. 3, in this eleventh embodiment, a mount boss 112 for mounting the compressor 111 at a predetermined place is disposed at a position farther from a clutch portion, in the example shown in the figure, from the position of pulley 15. Namely, a distance L between pulley 15 and mount boss 112 is set greater. On the contrary, it is possible to set the distance L smaller. Thus, the compressor 111 can also be designed freely in consideration of convenience in mounting. Because the other structures are similar to those in the aforementioned first embodiment, explanation is omitted by providing the same symbols as those in FIG. 1 to FIG. 11.

INDUSTRIAL APPLICATIONS OF THE INVENTION

The structure of the scroll fluidic device according to the present invention can be applied basically to any of scroll compressor and scroll expander, and in particular, it is suitable as a compressor for an air conditioning system for vehicles to which reduction of suction pressure loss, reduction of discharge pulsations, reduction of noise, and further, making small in size and light in weight are strongly required.

EXPLANATION OF SYMBOLS

-   1, 21, 31, 41, 51, 61, 71, 81, 91, 101, 111: scroll compressor as     scroll fluidic device -   2: fixed scroll member -   2 a: end plate of fixed scroll member -   2 b: scroll lap of fixed scroll member -   3: movable scroll member -   3 a: end plate of movable scroll member -   3 b: scroll lap of movable scroll member -   4: rotation preventing mechanism -   5: fluid pocket -   6, 24, 42: front housing -   7: rear housing -   8, 22, 32, 66, 76, 86, 103: center housing -   8 a, 32 a: outer shell of center housing -   8 b: end plate of outer shell of center housing -   9, 44, 95, 104: suction port -   10, 93: suction chamber -   11: discharge hole -   12: discharge chamber -   13, 65, 75, 85, 96: discharge port -   14: drive shaft -   15: pulley -   16: electromagnetic clutch -   17: crank mechanism -   18, 25, 43: corridor-like space -   19, 23, 62, 72, 82: thickness relief portion -   33 a, 33 b: wall -   34: recessed outer surface -   42 a: inner circumference of front housing -   52: oil storage chamber -   53: filter -   54: orifice -   62, 72, 82: second discharge chamber formed by thickness relief     portion -   63, 73, 83: first discharge chamber -   64, 74, 84: throttled portion -   77: gasket -   87: communication hole -   92: partition wall -   94: communication path -   102: suction path -   112: mount boss 

1. A scroll fluidic device wherein a scroll lap is formed on an end plate of a fixed scroll member integrally with the end plate, a scroll lap is formed on an end plate of a movable scroll member integrally with the end plate, both scroll members are disposed so that angles of both scroll laps are shifted from each other and side walls of both scroll laps are partially brought into contact with each other, and a volume of a fluid pocket, which is a closed space formed between both scroll laps, is changed by moving said fluid pocket from an outer end section of the scroll laps toward a center section of the scroll laps or from the center section of the scroll laps toward the outer end section of the scroll laps by revolving said movable scroll member on a circular orbit at a condition preventing rotation of said movable scroll member, characterized in that said fixed scroll member is integrally formed with a center housing, which is disposed between a front housing and a rear housing of the scroll fluidic device, in said center housing; an end surface of an outer shell of said center housing is positioned lower than a height of said scroll lap of said fixed scroll member, with said end plate of said fixed scroll member served as a reference of position in a height direction; and a corridor-like space extending in a device circumferential direction, which is surrounded by an outer shell forming portion of said center housing, an inner surface of an outer shell of said front housing, said scroll lap of said fixed scroll member, and said end plate of said movable scroll member, is formed.
 2. The scroll fluidic device according to claim 1, wherein, at a phase angle at which a distance between an inner surface of an outer circumferential end of said scroll lap of said movable scroll member and an outer surface of said scroll lap of said fixed scroll member facing to said inner surface of said outer circumferential end of said scroll lap of said movable scroll member becomes maximum, a cross-sectional area A1 of said corridor-like space satisfies the following relationship with a sectional area A2 of a port provided on said front housing. A2/2<A1<A2
 3. The scroll fluidic device according to claim 1, wherein said corridor-like space is always opened to a suction chamber of suction fluid or a discharge chamber of expansion fluid which is positioned at a side opposite to a side of said fixed scroll member with reference to said end plate of said movable scroll member.
 4. The scroll fluidic device according to claim 1, wherein a port directly fronting said corridor-like space is provided to said front housing.
 5. The scroll fluidic device according to claim 1, wherein, on an outer surface side of said outer shell of said center housing, a recessed outer surface of said outer shell having a predetermined thickness is formed relatively to a wall forming a wall surface, which contributes to change of volume of said fluid pocket, and a wall forming a wall surface, which faces said corridor-like space, of said scroll lap of said fixed scroll member.
 6. The scroll fluidic device according to claim 1, wherein, on an inner surface side of said outer shell of said center housing, a cup-like thickness relief portion extending in the same direction as said height direction of said scroll lap of said fixed scroll member is provided between a wall forming a wall surface, which contributes to change of volume of said fluid pocket, of said scroll lap of said fixed scroll member, and a wall forming an outer surface of said outer shell.
 7. The scroll fluidic device according to claim 6, wherein said thickness relief portion opens toward a side of said rear housing.
 8. The scroll fluidic device according to claim 7, wherein said thickness relief portion forms a second discharge chamber communicating with a first discharge chamber formed in said rear housing via a throttled portion to form a scroll compressor.
 9. The scroll fluidic device according to claim 8, wherein a discharge port from said second discharge chamber is provided to said center housing.
 10. The scroll fluidic device according to claim 8, wherein said throttled portion is formed by an inner outline of a gasket sealing between said center housing and said rear housing and an outline of an opening portion of said second discharge chamber.
 11. The scroll fluidic device according to claim 8, wherein a discharge port from said second discharge chamber is provided to said rear housing.
 12. The scroll fluidic device according to claim 7, wherein said thickness relief portion forms an oil storage chamber communicating with a discharge chamber formed in said rear housing for storing oil present in said discharge chamber to form a scroll compressor.
 13. The scroll fluidic device according to claim 12, wherein a filter is provided between said oil storage chamber and said discharge chamber.
 14. The scroll fluidic device according to claim 12, wherein said oil storage chamber and said corridor-like space are communicated with each other through an orifice.
 15. The scroll fluidic device according to claim 7, wherein a discharge chamber and a suction chamber are formed via a partition wall in said rear housing, and said suction chamber communicates with said corridor-like space through said thickness relief portion, to form a scroll compressor.
 16. The scroll fluidic device according to claim 6, wherein said thickness relief portion opens toward a side of said front housing.
 17. The scroll fluidic device according to claim 16, wherein a cross-sectional area of said thickness relief portion changes in said device circumferential direction.
 18. The scroll fluidic device according to claim 16, wherein said thickness relief portion communicates with said corridor-like space.
 19. The scroll fluidic device according to claim 18, wherein a suction port to said corridor-like space is provided to said center housing to form a scroll compressor.
 20. The scroll fluidic device according to claim 1, wherein said scroll fluidic device is used as a compressor for an air conditioning system for a vehicle. 